Roller leveller with double end drive



Feb. 7, 1956 R. 'r. TODD 2,733,750

ROLLER LEVELLER WITH DOUBLE END DRIVE Filed June 19. 1951 2 Sheets-Sheet l all INVENTOR RUSSELL T. TODD ll BY ATT RNEY Feb. 7, 1956 R. T. TODD 2,733,750

ROLLER LEVELLER WITH DOUBLE END DRIVE Filed June 19, 1951 2 Sheets-Sheet 2 INVENTOR RUSSELL T. TODD United States Patent 2,733,150 RGISLERLEVELLER WITH DOUBLE END DRIVE Russell. Todd, Youngstown, Ohio, assignor to The McKay Machine Company, Youngstown, Ohio, a cor- This-invention relatesto roller levellers for processing metal sheets and strips or the like and more particularly'to animproved meansofi motivating suchmachines whereby the useful life of'themachine may be increased and a product of higher quality may be obtained therefrom.

The process of levelling metal sheets and the like by means subjecting them to a-series of gradually diminishing flexures is well known in the art and machines for carrying out this process are in widespread use at the present time. A common means of causing these flexures is to pass the metal between layers-of rolls arranged in staggered relation. The metal, being forced to partially follow the con-tours of the rolls, is consequently flexed first inone direction and then in the other.

Experience has demonstrated that the quality of smoothness and evenness obtained by this process is dependent upon the severity of the sinuous path taken by themetal. Rollsof small diameter, having small radii of curvature, force'the material into more acute bends orflexures and have, therefore, been found to'be most efiecti-vefor this type of process. Small rolls are further advantageous in that a greater number of bending cycles maybe made in a given linear distance than with rolls of a larger-diameter, and thuslevelling machines may be made smaller and lighter yet operate with equal or superior elfectiveness. Since, however, a more acute bend requires a force of greater magnitude, problemshave been encountered involving undue stressing of the operating parts. If any but the very thinnest of sheet or strip is to be processed therolls will besubject to deflection caused by these bending forces. This is especially true if the rolls are of considerable length, as in; levelling wide strip and sheets,

D flection of the rolls; ccurs intwo forms; in trans verse bending and in torsion. The first formis quite obvious and is eliminated by the use of back-up rolls placed above, between and in longitudinal contact with pairs of levelling rolls. By this means the forces exerted upon the levelling rolls are partially transmitted to the back-up rolls. As many rows of such rolls may be used asis: necessary to efiectively eliminate this deflection.

r Thesecond form of deflection, that ;in torsion, is much more difficult to perceive than the. first and has, in general, been neglected in prior machines. These machines generally have, m ans ofmctivatioma source of power connected to. one end of each of the levelling rolls. This condition ,causes the existence-of .a torque. gradient across the entire length" of the roll, thus causing a torsional deflection or twisting of the roll. In the case of wide stock requiring sharp bends for proper working this results in a product having a surface that is imperfect due to the occurrence of small wrinkles and slip markings. It is the primary object of this invention to eliminate this undesirable torsional deflection of the working rolls of a leveller and this is accomplished by providing a means of rotating the levelling rolls from a single source of power 7 2,733,750 Patented 7 1956:"

connected to both: ends of the rollsto thereby supply approximately half the driving power at each end;

Due tothe fact that at least one, and preferably both, sets of rolls must be movable to permit adjustment for size variation and for proper processing of the irregularh ties of the metal, some form of flexible-connection must exist between the rolls and the source of power. For this purpose, universal joints are usually provided to connect the rolls to-a speed-reducing gear box. However,- universal' joints are 'weak driving linksunderconditions of heavy loading, especiallyif any shock orimpact occurs.

It is accordingly a further object of my invention to provide an improved means of driving roller levellers whereby conditions of shock or impact during loading is reduced or eliminated to thereby increase the longevity of thedriving linkage, and thereby reduce the costs of maintaining levelling machines in operative condition.

A still further object of the invention is to provide, inaroller levcller-having means to drive both ends of the working rolls thereof, an improved driving mechanisrn whereby the driving torque required to'drive the rolls will be equally distributed bet-ween both ends of the rolls and thus also between the opposite sets of universal joints or'wobblers used toconnect the rolls with the rolldriving gear boxes oftho leveller assembly.

The invention also seeks-to provide a roller leveller which will operate with smoothness and precision, without chatter asresults from roll: slippage or from torsion spring rebound action of small-diametered working rolls. Thus, thestock processed is free from anymarking and the machine will have longuseful life with minimum of maintenance. D

Other objects and advantages of the invention will become apparent upon consideration of the following detailed specification and accompanying drawing wherein there. is disclosed a certain preferred embodiment of my invention. r

In the drawing:

Figure l is: a plan viewof aroller leveller showing a power source and driving linkage arranged according to the principles of my invention; V

Figure 2 is a fragmentary cross-section taken at 1-1 of Figure 1 showing the general configuration ofthe levelling and backing rolls; and

-Figure 3 is. a front elevation of the roller leveller of Figure '1 showing the driving linkage positioned at each end of the levelling rolls. In. accordance with usual practice, the roller leveller illustrated comprisesa plurality of cylindrical levelling rolls 10 arranged in rows with the rolls of one row positioned instaggered relation to those of the otherrow to. provide a sinuous path therebetween. Suit-able backup rolls 11 are provided to contact the levelling rolls 10 longitudinally to prevent or reduce any transverse deflection which might otherwiseoccur due to the large forces exerted on the levelling rolls 10 during operation. Crushing rolls 12 are provided at the entrance slit 33 to reduce any extreme irregularities in the incoming stock toa suflicient degree to allowit to pass into the processing rolls. The levelling rolls 10 and their cooperating back-up rolls 11 are placed in banks as shown in Figure 2. Ordinarily these banks are movable with respect to each other to provide vertical adjustment and to allow tilting in both axial and transverse directions. This adjustment may be made by the hand wheel shown at 13, or by a power device as shown at 14.

I have provided a heavy base member 20 which supports the levelling apparatus at its mid-section and a gear box 19 at each of its ends. According to the principles of the invention, each crushing roll 12 and each levelling roll 10 is connected at each end to a gear box 19 by ing inboxes 19 is so designed that each roll will have an equal peripheral velocity. A pinch roll, not shown, may or may not be provided at the exit end of the leveller to pull the metal through the machine. Such pinch rolls often have a peripheral speed slightly in excess of that of the other rolls so that a slight stretching of the material is effected as it passes out of the machine. Extending outwardly from each gear box 19 is a shaft 21.. Sprocket wheels 22 are secured at their outer ends to provide means for transmitting power into the gear boxes 19.

At the back of the base member 20, and secured to the vertical wall thereof, I have provided a heavy duty motor 23 whose armature shaft 24 extends from both ends in a horizontally disposed manner. Fluid couplings 25 and 26 of a standard commercial design connect the armature shaft 24 with short intermediate shafts 27, which in turn are connected to the inner ends of flexible couplings 28. Connecting the other ends of the flexible couplings 28 are driving shafts 29. Each driving shaft 29 is guided and supported by means of journal posts 30 secured to and extending from the back wall of the base member 20. A driving sprocket 31 is secured to the outer end of each driving shaft 29. Said sprockets 31 are positioned to be in alignment with the driven sprocket wheels 22. Chains 32 transmit the motion of the driving sprockets 31 to the upper or driven sprocket wheels 22. A positive driving means between shafts 29 and 21 such as has been described is not essential, however, and could be replaced by suitable friction driving means. A positive means does, nevertheless, provide the most desirable operating characteristic since it is likely that the power loss through friction means would not be equal at both sides of the machine.

It should now be apparent that I have provided improvements in motivating means for roller levellers which accomplish the objects initially set forth. The double end drive I have provided permits the use of smaller levelling rolls to thereby provide for the production of sheet stock of superior smoothness and evenness. Torsional deflection, usually present to a considerable degree in prior machines is reduced up to seventyfive percent in machines using my proposed double end drive. Wrinkles and other surface defects in the stock processed which are caused by such torsional deflection are, therefore, almost completely eliminated by my invention. a

The use of a fluid-coupled source of power to each end drive for the working rolls of the leveller insures accurate division of the driving torque and renders the driving linkage shock absorbing as will be understood. Where in prior machines any shock or impact due to the sudden insertion of stock into the machine was transmitted throughout the driving linkage, including the impactsensitive universal joints or wobblers, my linkage will resiliently absorb much of such impact in the fluid coupling. Maintenance of roller levellers is thus greatly reduced since generallythe most vulnerable links of the machine are the universal joints.

The above specifically described embodiment of my invention should, however, be considered as illustrative only, as many obvious alterations may be made therein without departing from the spirit or scope of the invention. Reference should therefore be made to the following appended claims to determine the scope of the invention.

I claim:

1. In a roller leveller having a plurality of elongated small-diametered working rolls arranged in spaced ofi-set relations to define a sinuous path for sheet or strip stock therebetween the combination of a base rotatably supporting said rolls and extending outwardly from each end thereof, said driving shafts constituting the primary driving means for said rolls, a gear train assembly at each end of said base and mounted thereon and having a plurality of inwardly directed driving shafts, fiexible couplings interconnecting said driving shafts and the adjacent ends of said rolls whereby the latter may be driven from both ends, eacn of said gear train assemblies having a power input shaft, a single driving motor mounted on said base and having its armature shaft extending outwardly from both ends thereof, a pair of longitudinally spaced but axially aligned drive shafts journaled on said base outwardly of said motor and each coupled with an adjacent one of said power input shafts, said armature shaft being axially aligned with the last mentioned drive shafts, and a pair of fluid couplings interconnecting the ends of said armature shaft with said last mentioned drive shafts.

2. In a roller leveller having a plurality of spaced parallel elongated and small-diametered working rolls ar-, ranged to define a sinuous path of travel for sheet or strip stock therebetween the combination of a driving assembly at each end of said rolls and coupled with the adjacent ends thereof whereby said rolls are driven from both ends, said driving assembly constituting the primary driving means for said rolls, a single mechanical power source comprising a rotating shaft having two free ends, and a pair of fluid couplings interconnecting the respective ends of said rotating shaft with said driving assemblies whereby substantially equal driving torque is applied to said driving assemblies.

3. In a roller leveller the combination of an elongated base, a pair of spaced housings mounted on the central portion of said base, a plurality of spaced parallel elongated and small-diametered working rolls journaled at their ends in said housings and disposed in staggered relation to define a sinuous path of travel for sheet or strip stock therebetween, a gear drive assembly mounted on each end of said base outwardly of said housings and each having a plurality of output shafts coupled individually with the adjacent end portions of said working rolls and constituting the primary means of driving said rolls, each of said gear drive assemblies having an input shaft, single rotative power means coupled with said input shafts whereby said working rolls are driven by the application of driving torque to the opposite ends thereof, said input shafts extend outwardly longitudinally of said. base, said power means comprising an electric motor mounted on the side of said base but below the path of travel of the stock through said working rolls and having a double ended shaft extending substantially parallel with said input shaft. I

References Cited in the file of this patent UNITED STATES PATENTS a L s 

